For the Windsor, considering the heads and bottom end are in good enough condition to warrant performance work. I would recomend a cam with about
[email protected] for the intake and about
[email protected] for the exhaust duration. or even up to 10 more degrees on the exhaust in comparison to the intake duration. This is because this head has a somewhat poor port flow balance, being bad on the exhaust's part. When choosing a cam, look for a cam with a fast ramp, with
[email protected] the advertised duration should be about 260-270ish, any higher would not be a fast ramp. For the
[email protected] you'd want about 268-278ish for advertised duration. For your lobe seperation, the wider the better, I would recomend 112 for this. Although Comp's Extream Energy series has Windsor cam with about the right specs for your application with 260/210 int, 268/218ex with a 111 lobe sep. This would still work well with the 111 since the advertised values are low. This would be the about the biggest cam to install in this application. You could even figure another 5 degrees less on each duration if you felt it'd better suit your desired use of the car.
The reason I pick these numbers for the cam is they offer good torque and hp through the mid range and start at a low enough rpm that you won't be forced to install a big gear in the rear and a high stall convertor like what you'd need to match a bigger cam.
Matching componants correctly is really what makes for a good running motor.
For the carb I would recomend a 600 Edelbrock. The reason for the Edelbrock is it is so much easier to tune then a Holley. I'm not saying Edelbrock is a more efficiant carb then a Holley, but when it comes to consistant running and holding a tune, the Edelbrock is better. Also they don't spontainiously leak. I have had plenty of Holleys and now run Edelbrocks on all my vehicles. For any carb, make sure you use two return springs, in the case if one breaks for safety issues.
You can go with either a stock 1969 4v Windsor intake or use an Edelbrock Performer. No other intake beats the stock 4v in torque up to 4000rpm's. The Performer will have just a little more hp on top.
With the ignition, my favorite ignition set up is a Ford Duraspark distributor used in conjunction with an MSD 6AL box. The duraspark is fairly easy to set up the timing range and curve. They are under 50 bucks at the auto parts store for a rebuilt distributor. The MSD is about 175 from Summit or Jeg's. To me, it is worth it. I have found that I was able to lean out the idle mix slightly while still maintaining a smooth idle. I did find that when I went from the Duraspark ignition box to the MSD, I didn't get any improvment in my cruising mileage. The duraspark box seemed to be set up really well for that range. Also, the MSD 6AL box has rev limiter protection. The cheaper MSD 6A does not has a rev limiter. It is easier to set up the Duraspark dist with an MSD then it is to set up the Duraspark dist with a Duraspark ignition box. So I'd recomend just to skip over the stock box since the MSD fully replaces it.
Run a K&N air cleaner and tune your car with it in place. If you tune with a paper element then go to K&N, you willhave to retune your carb----it happened to me. The K&N makes that much difference in an increase of airflow that I had to richen my carb to compensate.
I would not recomend headers. Even though your hp would be better, they are noisy no matter what muffler you have and they radiate excess heat. Usually you have to run that silly power steering drop bracket which will pull out the pressed in nuts after some driving. I am looking to go back to exhaust manifolds because the droaning noise which resonates off the header tubes just fills the car and really becomes a nusance in a short time of driving. I love getting in my convertible because it has exhaust manifolds----and all the sound comes out the back of the car. I can actually talk without rasing my voice to the person sitting in the passenger's seat---and they can hear me. I can't do that in my car with headers, I always have to yell. Headers are good when you are looking every last bit of HP. If you look at manifolds the flow restriction is quite appearant, but you have to think of the application the car will be used in. 99% of the time you will be cruisng and the exhaust gas load will be low and well within the capacity of the manifolds. The only time you'd have wanted headers is when your foot is to the floor and shifting at 5500 rpms. With the manifolds you may be losing 10-15 hp on the top in that 1% of when the car is at WOT. With headers, you will be losing some comfort for the 99% of the time and make it not so pleasant to go out on a cruise. Having the extra 8-10 degrees for the exhaust duration is partially for the sake of keeping the exhaust manifolds. The bare cylinder heads port flow relationship does warrant more exhaust duration, but only about 5 degrees. I like to add anoter 3-5 degrees for exhaust manifolds depending on what exhaust pipe diameter you are running. I'd recomend 2 1/4 pipe with a crossover. The exhaust shop must position the cross over far enough back as to not make a restriction when pulling out the trans. They can actually make a small H type crossover over that convertible reinforcement plate. 2 1/4 is the biggest you'd want to go with this engine combination, 2 inch would suffice because of the 99% versus 1%, and be easier for the exhaust shop to install. The smaller pipe will be quieter and offer somewhat better off idle torque.
The next mod after all this to the engine would be an overdrive transmission, be it an automatic AOD or a 5 speed manual---that is the ultimate for cruising on the highway.
I hope this offers some guidance in setting up your engine to make a great cruiser.